Modern data processing systems are developed from multifunction chips having capabilities of performing many hundreds of functions, receiving many instructions and processing a wide range of data, and in particular alphanumeric data. Manual keyboard entry techniques have not kept up with the significant increase in capacity and comprehensiveness necessary to permit the effective use of the increased chip capabilities and thus have been a significant bottleneck to the advance of the manual entry data processing art.
In many instances a keyboard with few keys located in a limited space is necessary, as in the case of pocket size computers, or those designed for "touch" entry with a single hand so that the other hand may refer to records, etc. as in the case of an accounting system. Yet the trend is to go to larger and larger keyboards to increase the capabilities of communication with modern data processing chips.
Typical art permitting a keyboard system to be used in different modes thus producing multiple use of the keys is exemplified in the referenced application, in U.S. Pat. No. 4,124,843 by H. G. Bramson et al. for "Multi-Lingual Input Keyboard and Display", Nov. 7, 1978, and in U.S. Pat. No. 3,892,958 by C. C. Tung for "Inverse/Complementary Function Prefix Key", July 1, 1975. In such cases each key can achieve several functions to communicate with a larger number of the chip functions than a single mode keyboard.
In the referenced application the keyboard capabilities are even further increased by adopting a multiple keystroke mode of operation that permits a single key to achieve multiple functions in each operating mode, depending upon whether one or more sequential strokes of the key are employed. There is, however, a price to pay for the significantly expanded range of functions available, namely, the time it takes for entry of data, and the increased chance for operator error. That is, if in order to provide alphanumeric operation a key need be stroked twice for each alphabetic character entry, it is obviously a tedious and time consuming process as compared with using a typewriter.
The problems of coordinating the multiple stroke operational mode of the foregoing application in a "touch" entry manual keyboard by an operator are significant. Also, when the number of keys become significantly larger than the number of fingers as in the foregoing patent, it is not a good environment for "touch" entry because of the frequent need to reposition the fingers and the thus significantly increased chance for operator error.
For appropriate manual entry of alphanumeric data into a touch entry system, it is highly desirable to have access to the entire alphabet plus a reasonable number of punctuation and instruction keys. A conventional typewriter keyboard generally has over forty keys in a bulky array requiring use of both hands to achieve this. These are requirements not always suitable in a data processing system and are certainly not compatible with the pocket sized systems now conventional in the art.
Feedback is most important in a touch system, namely, the ability of the operator to know that the entry is completed. This is achieved in a satisfactory manner by the movement stroke of a typewriter key. Without key movement it is most difficult to coordinate timing and to reduce manual error selections.
Also error free operation needs eliminate the operator errors induced by decision making. In the typewriting art it is well established that faster error free typing occurs when thinking is not required only copying mechanically from a text. For example, U.S. Pat. No. 4,042,777 for "One-Handed Keyboard and Its Control Means", Aug. 16, 1977 requires a thinking decision in selection of a plurality of keys constituting a chord. For sensitive data such as accounting records, etc., it is evident that operator's errors are frequently induced by decisions in choosing the "chords".
Therefore, this invention has the objective of improving the state of the art by significantly increasing the capability of a manual entry data processing keyboard to communicate with a modern data processing system in a time saving convenient manner using fewer strokes, fewer keys, and adapatable to the "touch" system of manual entry for fast data entry.